The North-West outfit managed to secure a 1-1 draw with Shakhtar Donetsk on Wednesday, but Vidic thinks that getting a result at the Stadium of Light is imperative.
"I think this is actually a more important game, even though it was Shakhtar in the Champions League," Vidic told the club's official website. "I think we have to perform well at Sunderland, like we did against Shakhtar, in terms of our defending.
"With the quality we have up front, we are always able to score goals. I think there's no question about that, but we have to defend right and have the right mentality to ensure we can be in a good position."
United have lost three of their six league matches.